1 files changed, 151 insertions, 0 deletions
diff --git a/contrib/plugins/stoptrigger.c b/contrib/plugins/stoptrigger.c
new file mode 100644
index 0000000..03ee22f
--- /dev/null
+++ b/contrib/plugins/stoptrigger.c
@@ -0,0 +1,151 @@
+/*
+ * Copyright (C) 2024, Simon Hamelin <simon.hamelin@grenoble-inp.org>
+ *
+ * Stop execution once a given address is reached or if the
+ * count of executed instructions reached a specified limit
+ *
+ * License: GNU GPL, version 2 or later.
+ *   See the COPYING file in the top-level directory.
+ */
+
+#include <assert.h>
+#include <glib.h>
+#include <inttypes.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+#include <qemu-plugin.h>
+
+QEMU_PLUGIN_EXPORT int qemu_plugin_version = QEMU_PLUGIN_VERSION;
+
+/* Scoreboard to track executed instructions count */
+typedef struct {
+    uint64_t insn_count;
+} InstructionsCount;
+static struct qemu_plugin_scoreboard *insn_count_sb;
+static qemu_plugin_u64 insn_count;
+
+static uint64_t icount;
+static int icount_exit_code;
+
+static bool exit_on_icount;
+static bool exit_on_address;
+
+/* Map trigger addresses to exit code */
+static GHashTable *addrs_ht;
+
+static void exit_emulation(int return_code, char *message)
+{
+    qemu_plugin_outs(message);
+    g_free(message);
+    exit(return_code);
+}
+
+static void exit_icount_reached(unsigned int cpu_index, void *udata)
+{
+    uint64_t insn_vaddr = GPOINTER_TO_UINT(udata);
+    char *msg = g_strdup_printf("icount reached at 0x%" PRIx64 ", exiting\n",
+                                insn_vaddr);
+
+    exit_emulation(icount_exit_code, msg);
+}
+
+static void exit_address_reached(unsigned int cpu_index, void *udata)
+{
+    uint64_t insn_vaddr = GPOINTER_TO_UINT(udata);
+    char *msg = g_strdup_printf("0x%" PRIx64 " reached, exiting\n", insn_vaddr);
+    int exit_code;
+
+    exit_code = GPOINTER_TO_INT(
+        g_hash_table_lookup(addrs_ht, GUINT_TO_POINTER(insn_vaddr)));
+
+    exit_emulation(exit_code, msg);
+}
+
+static void vcpu_tb_trans(qemu_plugin_id_t id, struct qemu_plugin_tb *tb)
+{
+    size_t tb_n = qemu_plugin_tb_n_insns(tb);
+    for (size_t i = 0; i < tb_n; i++) {
+        struct qemu_plugin_insn *insn = qemu_plugin_tb_get_insn(tb, i);
+        gpointer insn_vaddr = GUINT_TO_POINTER(qemu_plugin_insn_vaddr(insn));
+
+        if (exit_on_icount) {
+            /* Increment and check scoreboard for each instruction */
+            qemu_plugin_register_vcpu_insn_exec_inline_per_vcpu(
+                insn, QEMU_PLUGIN_INLINE_ADD_U64, insn_count, 1);
+            qemu_plugin_register_vcpu_insn_exec_cond_cb(
+                insn, exit_icount_reached, QEMU_PLUGIN_CB_NO_REGS,
+                QEMU_PLUGIN_COND_EQ, insn_count, icount + 1, insn_vaddr);
+        }
+
+        if (exit_on_address) {
+            if (g_hash_table_contains(addrs_ht, insn_vaddr)) {
+                /* Exit triggered by address */
+                qemu_plugin_register_vcpu_insn_exec_cb(
+                    insn, exit_address_reached, QEMU_PLUGIN_CB_NO_REGS,
+                    insn_vaddr);
+            }
+        }
+    }
+}
+
+static void plugin_exit(qemu_plugin_id_t id, void *p)
+{
+    g_hash_table_destroy(addrs_ht);
+    qemu_plugin_scoreboard_free(insn_count_sb);
+}
+
+QEMU_PLUGIN_EXPORT int qemu_plugin_install(qemu_plugin_id_t id,
+                                           const qemu_info_t *info, int argc,
+                                           char **argv)
+{
+    addrs_ht = g_hash_table_new(NULL, g_direct_equal);
+
+    insn_count_sb = qemu_plugin_scoreboard_new(sizeof(InstructionsCount));
+    insn_count = qemu_plugin_scoreboard_u64_in_struct(
+        insn_count_sb, InstructionsCount, insn_count);
+
+    for (int i = 0; i < argc; i++) {
+        char *opt = argv[i];
+        g_auto(GStrv) tokens = g_strsplit(opt, "=", 2);
+        if (g_strcmp0(tokens[0], "icount") == 0) {
+            g_auto(GStrv) icount_tokens = g_strsplit(tokens[1], ":", 2);
+            icount = g_ascii_strtoull(icount_tokens[0], NULL, 0);
+            if (icount < 1 || g_strrstr(icount_tokens[0], "-") != NULL) {
+                fprintf(stderr,
+                        "icount parsing failed: '%s' must be a positive "
+                        "integer\n",
+                        icount_tokens[0]);
+                return -1;
+            }
+            if (icount_tokens[1]) {
+                icount_exit_code = g_ascii_strtoull(icount_tokens[1], NULL, 0);
+            }
+            exit_on_icount = true;
+        } else if (g_strcmp0(tokens[0], "addr") == 0) {
+            g_auto(GStrv) addr_tokens = g_strsplit(tokens[1], ":", 2);
+            uint64_t exit_addr = g_ascii_strtoull(addr_tokens[0], NULL, 0);
+            int exit_code = 0;
+            if (addr_tokens[1]) {
+                exit_code = g_ascii_strtoull(addr_tokens[1], NULL, 0);
+            }
+            g_hash_table_insert(addrs_ht, GUINT_TO_POINTER(exit_addr),
+                                GINT_TO_POINTER(exit_code));
+            exit_on_address = true;
+        } else {
+            fprintf(stderr, "option parsing failed: %s\n", opt);
+            return -1;
+        }
+    }
+
+    if (!exit_on_icount && !exit_on_address) {
+        fprintf(stderr, "'icount' or 'addr' argument missing\n");
+        return -1;
+    }
+
+    /* Register translation block and exit callbacks */
+    qemu_plugin_register_vcpu_tb_trans_cb(id, vcpu_tb_trans);
+    qemu_plugin_register_atexit_cb(id, plugin_exit, NULL);
+
+    return 0;
+}